uni_ass.6 8.3 KB

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  1. .\" $Id$
  2. .TH UNI_ASS 6 "$Revision$"
  3. .ad
  4. .SH NAME
  5. uni_ass \- universal assembler, assembler\-loader
  6. .SH SYNOPSIS
  7. ~em/lib.bin/\fImach\fP/as [options] argument ...
  8. .SH DESCRIPTION
  9. The universal assembler is a framework allowing easy
  10. generation of an assembler for any byte oriented machine.
  11. The framework includes common pseudo instructions for name
  12. definition, label usage, storage allocation and initialization
  13. and expression evaluation.
  14. The resulting program assembles assembly modules.
  15. For some machines, it also does the link-editing (loading).
  16. Arguments may be flags, assembly language modules, or,
  17. in the case of an assembler\-loader,
  18. .IR arch (1)
  19. libraries.
  20. .br
  21. Flags are:
  22. .IP \-d\fIonum\fP
  23. This option controls the listing. Default is no listing.
  24. .I Onum
  25. is interpreted as an octal number.
  26. Each bit controls part of the listing as follows:
  27. .RS
  28. .nf
  29. 0001: addresses in pass 1
  30. 0002: generated code in pass 1
  31. 0004: not used
  32. 0010: addresses in pass 2
  33. 0020: generated code in pass 2
  34. 0040: source lines in pass 2
  35. 0100: addresses in pass 3
  36. 0200: generated code in pass 3
  37. 0400: source lines in pass 3
  38. 1000: force .list and ignore .nolist
  39. .fi
  40. .RE
  41. Thus bits in 0 to 8 control the listing format and
  42. bit 9 forces a complete listing.
  43. If
  44. .I onum
  45. is omitted or is 000 it is interpreted as 0700.
  46. If
  47. .I onum
  48. is 1000 it is interpreted as 1700.
  49. .br
  50. Note that '-d' alone (unless it contains bit 9)
  51. is not enough to get a listing.
  52. A .list pseudo is also needed in each module to be listed.
  53. Assemblers may be compiled with the listing facilities disabled.
  54. .IP -s[\fIonum\fP]
  55. This option controls the
  56. amount of symbolic debug information generated.
  57. .I Onum
  58. is interpreted as an octal number.
  59. The bits have the following meaning:
  60. .RS
  61. .nf
  62. 001: external symbols
  63. 002: local symbols
  64. 004: local, compiler generated labels
  65. 010: symbols defined in
  66. .I .symb
  67. pseudo instruction
  68. 020: records for
  69. .I .line
  70. and
  71. .I .file
  72. statements
  73. 040: section names
  74. .fi
  75. .RE
  76. Default is 073: all except local compiler labels.
  77. .IP -r
  78. Generate relocation information, for assemblers\-loaders that can.
  79. Assemblers always produce relocation information.
  80. .IP -b
  81. Turn off branch optimization.
  82. .IP -o\fIname\fP
  83. .IP -"o \fIname\fP"
  84. .I name
  85. is taken as the name of the
  86. resulting load file.
  87. The default name is \fBa.out\fP.
  88. .PP
  89. The assembler\-loaders assemble
  90. and link together assembly language modules
  91. machine
  92. from files and libraries,
  93. producing an \fIack.out\fP(5) format file, without relocation information.
  94. The assemblers produce a relocatable \fIack.out\fP(5) format file.
  95. .PP
  96. Two different types of arguments are allowed:
  97. .IP "1-"
  98. Assembly language modules
  99. .PD 0
  100. .IP "2-"
  101. UNIX archives, as maintained by arch(1). These archives must
  102. only contain
  103. assembly language modules with \fI.define\fP as their first
  104. statement.
  105. These are only accepted by assembler\-loaders.
  106. .PD
  107. .PP
  108. Note that assembler\-loaders cannot do a partial load;
  109. loading starts from assembly language and produces binary
  110. machine code. No relocation bits are produced.
  111. On the other hand, assemblers produce a relocatable file, to be handled
  112. by \fIled\fP(1).
  113. .SH "SECTIONS and TYPES"
  114. The statements allocating and initializing space,
  115. like instructions and
  116. some pseudo-instruction reserve that space in the current
  117. section.
  118. The currently reigning type of section is determined by
  119. the pseudo-instruction \fI.sect\fP.
  120. Actually, the assembler knows nothing about section types. Sections have
  121. numbers. The first section met gets number 0, the second gets number 1, etc.
  122. Therefore, every assembly files should start with a line just mentioning the
  123. sections used in the right order, so that no confusion can arise for \fIled\fP(1).
  124. .SH SYNTAX
  125. .PP
  126. The syntax of expressions is identical to the C expression syntax,
  127. except that square brackets are used for grouping.
  128. Labels are followed by a colon, and are identifiers or
  129. numbers between 0 and 9.
  130. Numeric labels can be referenced using the label followed by 'b' of 'f'
  131. determining the direction of search, backwards or forwards.
  132. .IP letters
  133. Both upper and lower case may be used and are seen as
  134. different.
  135. The underscore '_' is considered to be a letter.
  136. .IP identifiers
  137. Identifiers are a sequence of letters and digits, starting with
  138. a letter or a period '.'.
  139. Identifiers can, only once, receive a value through assignment or a
  140. label definition.
  141. .IP strings
  142. Strings are enclosed in single "'" or double """ quotes.
  143. The use of \eddd where ddd is an octal number and \en, \er,
  144. \et, \eb and \ef is allowed and has the same meaning as in the
  145. C language.
  146. .IP numbers
  147. Numbers are a sequence of letters and digits, starting with a
  148. digit.
  149. No difference is made between small and capital letters.
  150. .br
  151. The base of the number is determined in the following way:
  152. .nf
  153. if the number starts with '0x' it is hexadecimal else
  154. if the number starts with '0' it is octal else
  155. it's decimal.
  156. .fi
  157. The range of numbers depends on the machine.
  158. A rule of the thumb is that the width of the machine's registers
  159. the same is as the number of bits allowed in numbers.
  160. .IP comment
  161. The character '!' denotes the start of comment, every character
  162. up to the next newline is skipped.
  163. Exclamation marks in strings are not recognized as the start of
  164. comment.
  165. .IP statements
  166. Statements are separated by newlines and ';' and can be
  167. preceded by label definitions.
  168. Label definitions have the form "\fIidentifier\fP:" or
  169. "\fIdigit\fP:".
  170. Statements can be: empty, an assignment, an instruction or a
  171. pseudo-instruction.
  172. .IP assignment
  173. An assignment has the form:
  174. .br
  175. \fIidentifier\fP = \fIexpression\fP
  176. .br
  177. The identifier receives the value and type of the expression.
  178. .IP instruction
  179. The syntax of an instruction depends on the type of the target
  180. machine.
  181. .IP pseudo-instruction
  182. .de Pu
  183. .sp 1
  184. .ti +5
  185. \&\\$1
  186. .sp 1
  187. ..
  188. .Pu ".extern \fIidentifier [, identifier]*\fP"
  189. The identifiers mentioned in the list are exported and can be
  190. used in other modules.
  191. .Pu ".define \fIidentifier [, identifier]*\fP"
  192. Used for modules that are to be part of a libary.
  193. The .define pseudo's should be the first in such modules.
  194. When scanning a module in a library the assembler\-loader
  195. checks whether any of its unsatified external references is
  196. mentioned in a .define list. If so, it includes that module in
  197. the program.
  198. The identifiers mentioned in the list are exported and can be
  199. used in other modules.
  200. .Pu ".data1 \fIexpression [, expression]*\fP"
  201. Initialize a sequence of bytes.
  202. This is not followed by automatic alignment.
  203. .Pu ".data2 \fIexpression [, expression]*\fP"
  204. Initialize a sequence of shorts (2-byte values).
  205. This is not followed by automatic alignment.
  206. .Pu ".data4 \fIexpression [, expression]*\fP"
  207. Initialize a sequence of longs (4-byte values).
  208. This is not followed by automatic alignment.
  209. .Pu ".ascii \fIstring\fP"
  210. Initialize a sequence of bytes with the value of the bytes in
  211. the string.
  212. This is not followed by automatic alignment.
  213. .Pu ".asciz \fIstring\fP"
  214. Initialize a sequence of bytes with the value of the bytes in
  215. the string and terminate this with an extra zero byte.
  216. This is not followed by automatic alignment.
  217. .Pu ".align [\fIexpression\fP]"
  218. Adjust the current position to a multiple of the value of the
  219. expression.
  220. The default is the word-size of the target machine.
  221. .Pu ".space \fIexpression\fP"
  222. Allocate the indicated amount of bytes.
  223. The expression must be absolute.
  224. .Pu ".comm \fIname\fP,\fIexpression\fP"
  225. Allocate the indicated amount of bytes and assign the location of the first
  226. byte allocated to
  227. .IR name ,
  228. unless
  229. .I name
  230. is defined elsewhere.
  231. If the scope of
  232. .I name
  233. is extern, then assemblers leave definition of
  234. .I name
  235. to the linkeditor \fIled\fP(1).
  236. .Pu .sect \fIname\fP
  237. section name definition.
  238. .Pu ".base \fIexpresssion\fP"
  239. Set the starting address of the first of the consecutive segments
  240. (text) to the value of the expression.
  241. The expression must be absolute.
  242. .Pu .assert \fIexpression\fP
  243. assembly-time assertion checking. Stop with a fatal error message when
  244. the value of the expression is zero.
  245. .Pu .symb, .line, .file
  246. symbolic debug
  247. .Pu .nolist, .list
  248. .br
  249. listing control
  250. .SH "SEE ALSO"
  251. ack(1), arch(1), ack.out(5)
  252. .SH DIAGNOSTICS
  253. Various diagnostics may be produced.
  254. The most likely errors, however, are unresolved references,
  255. probably caused by the omission of a library argument.
  256. .SH BUGS
  257. The alignment might give rise to internal assertion errors when
  258. the alignment requestes is larger than the machine dependent
  259. segment alignment.
  260. .br
  261. Identifiers declared as externals cannot be used as locals in
  262. any following module. This only is a problem for assembler\-loaders.